He added that the Ministry of Defence (MoD) could not confirm how many trainees had rejoined factions in Syria.

“Whilst they might not all have been specifically trained by a British trainer, it is likely that most had interaction with a member of a British training team at some point during their tenure.”

“We cannot say with certainty how many of the trained Syrian opposition fighters are actively involved in military operations,” he said.

Howe said there is no evidence any of the trainees had joined Islamic State (formerly ISIS/ISIL), but said “some of the Syrian opposition fighters have been detained by extremist groups.”

The figures come as Prime Minister David Cameron continues to seek support from MPs to approve airstrikes in Syria against Islamic State targets.

It was reported Tuesday that the PM had unofficially scrapped a House of Commons vote over fears he would be humiliated by rebellious Conservative MPs. Downing Street rebuffed the claims, however, insisting Cameron is still garnering support for the measures.